Comments on Inner Multisite not working, 404 error on Post URL

Hard to say. Any error log messages? Does it do this for logged in users? what about turning the plugins off?

As I expected it was a .htaccess issue.

I added the following RewriteRule to the (inner) multisite .htaccess: RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-comments-post.*) $2 [L]

Entire file looks like this now:

RewriteEngine On
RewriteBase /demo/
RewriteRule ^index\.php$ - [L]

# uploaded files
RewriteRule ^([_0-9a-zA-Z-]+/)?files/(.+) wp-includes/ms-files.php?file=$2 [L]

# add a trailing slash to /wp-admin
RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d

RewriteRule ^ - [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) $2 [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-comments-post.*) $2 [L]

RewriteRule . index.php [L]

I hope this helps anyone and is a valid solution.

Cheers,
Fox

i am facing the same problem, when a user enter a comments ,after clicking the submit button https://webkotler.com/wp-comments-post.php pages come up.i changed .htaccess which is listed over.disable all plugins,change permalink to default,and uncheck break comments into pages, change theme, rename comment.php etc, plz if you have any other idea,share with us,,,

Regards,
Mark